The following commands, or symbolic links to commands, are required in /bin.
|cat||Utility to concatenate files to standard output|
|chgrp||Utility to change file group ownership|
|chmod||Utility to change file access permissions|
|chown||Utility to change file owner and group|
|cp||Utility to copy files and directories|
|date||Utility to print or set the system data and time|
|dd||Utility to convert and copy a file|
|df||Utility to report filesystem disk space usage|
|dmesg||Utility to print or control the kernel message buffer|
|echo||Utility to display a line of text|
|false||Utility to do nothing, unsuccessfully|
|hostname||Utility to show or set the system's host name|
|kill||Utility to send signals to processes|
|ln||Utility to make links between files|
|login||Utility to begin a session on the system|
|ls||Utility to list directory contents|
|mkdir||Utility to make directories|
|mknod||Utility to make block or character special files|
|more||Utility to page through text|
|mount||Utility to mount a filesystem|
|mv||Utility to move/rename files|
|ps||Utility to report process status|
|pwd||Utility to print name of current working directory|
|rm||Utility to remove files or directories|
|rmdir||Utility to remove empty directories|
|sed||The `sed' stream editor|
|sh||The Bourne command shell|
|stty||Utility to change and print terminal line settings|
|su||Utility to change user ID|
|sync||Utility to flush filesystem buffers|
|true||Utility to do nothing, successfully|
|umount||Utility to unmount file systems|
|uname||Utility to print system information|
If /bin/sh is not a true Bourne shell, it must be a hard or symbolic link to the real shell command.
The [ and test commands must be placed together in either /bin or /usr/bin.
The requirement for the [ and test commands to be
included as binaries (even if implemented internally by the shell) is shared with the POSIX.2 standard.
|csh||The C shell (optional)|
|ed||The `ed' editor (optional)|
|tar||The tar archiving utility (optional)|
|cpio||The cpio archiving utility (optional)|
|gzip||The GNU compression utility (optional)|
|gunzip||The GNU uncompression utility (optional)|
|zcat||The GNU uncompression utility (optional)|
|netstat||The network statistics utility (optional)|
|ping||The ICMP network test utility (optional)|
If the gunzip and zcat programs exist, they must be symbolic or hard links to gzip. /bin/csh may be a symbolic link to /bin/tcsh or /usr/bin/tcsh.
Conversely, if no restoration from the root partition is ever expected,
then these binaries might be omitted (e.g., a ROM chip root, mounting
/usr through NFS). If restoration of a system is planned
through the network, then ftp or tftp (along with
everything necessary to get an ftp connection) must be available on
the root partition.
 Command binaries that are not essential enough to place into /bin must be placed in /usr/bin, instead. Items that are required only by non-root users (the X Window System, chsh, etc.) are generally not essential enough to be placed into the root partition.